1813.] Scientific Intelligence. S?^ 



conceives that part of it is polarized, and that part of it remains 

 unaltered. We have only lo add, that a full account of these 

 interesting discoveries will be found in Dr. Brewster's treatise ou 

 new philosophical instruments, just published. 



III. Fungin, 



This name has been recently given by Braconnot to the fleshy 

 part of mushrooms, which he conceives to be a peculiar vegetable 

 principle ; and which, according to him, possesses the following 

 properties : — 



It may be obtained pure by boiling it in a weak alkaline solu- 

 tion. In that state it is whitish, soft, insipid, possesses little 

 elasticity, and readily yields to tlie teeth. It would appear that 

 fungiQ thus purified may be used as an article of food, from 

 what mushroom soever it has been obtained. The poisonous 

 qualities of mushrooms, it would seem, reside in the juices, not 

 in the fungin. This substance, when dried, burns with consi- 

 derable splendour, emitting an odour similar to that of burning 

 bread, and leaving behind it a white ash. 



Dried fungin, when distilled in a retort, yields about half its 

 weight of a liquid product, consisting partly of a brown oil, and 

 partly of water, holding a good deal of ammonia in solution. 

 It yields no acid, which distinguishes it very much from wood. 

 The charcoal remaining in the retort amounts to rather more 

 than one-fourth of the dry fungin subjected to distillation. This 

 charcoal exhibited traces of sulphureted hydrogen, and contained 

 Sand, phosphate of lime, and traces of carbonate of lime, phos- 

 phate of lime, and of alumina. 



Fungin does not dissolve in alkaline solutions, in which respect 

 it differs essentially from lignin, which is readily dissolved by a 

 weak alkali ; but if fungin be boiled in a very strong alkaline lie 

 it is partly dissolved, and a saponaceous product obtained. Am- 

 monia dissolves a small portion of fungin, and lets it fall again 

 in white flocks when exposed to the air. 



Weak sulphuric acid has no action on fungin; but wheh con- 

 centrated, this acid chars it, and at the same time sulphurous 

 acid and vinegar are formed. 



Muriatic acid dissolves it very slowly, and converts it into a 

 gelatinous matter. It is thrown down in flocks by the addition 

 of potash to the acid. Chlorine passed over dry lungin suspended 

 in water converts it into a yellow matter, having at first an acrid 

 taste, which it gradually loses by exposure to the air. 



When digested in diluted nitric acid, azotic gas is disengaged. 

 Heated with concentrated nitric acid, it swells, and effervesces, 

 at first violently, but the action soon subsides. When the acid 

 is" driven off there remains a liquor, containing oxalate of lime, 

 some prussic acid, and two fatty matters, the most abundant 



